The vehicle slide rail device of Patent Literature 1 is provided with a pair of left and right lower rails which are fixed to a vehicle interior floor, extend in the forward/rearward direction and include a large number of lock grooves arranged in a forward/rearward direction; a pair of left and right upper rails which support a seating portion of a seat and are slideably supported by the left and right lower rails; a pair of left and right lock-release levers which are rotatably supported on the left and right upper rails about an axis extending in the leftward/right direction, are disengageably engageable with the lock grooves, and are provided inside the inner space of the upper rails, respectively, except for front end portions thereof; a biaser which rotatably biases the lock-release levers in a direction to engage with the lock grooves; and a lock operational lever (loop handle), having an approximately U-shape in a plan view, the left and right rear end portions thereof being connected to the front end portions of the left and right lock levers.
When an occupant applies no operating force to the lock operational lever, the sliding of the upper rails relative to the lower rails is restricted since the lock-release lever is engaged with some of the lock grooves by the biasing force of the biaser. On the other hand, upon an occupant pulling up the lock operational lever, since each lock-release lever is released from the engagement with the lock grooves against the biasing force of the biaser, the upper rails can slide relative to the lower rails.